[Jacob-list] Fw: Grain'-n-grazin'

[Grose]

----- Original Message ----- 
From: Grose 
To: Jacoblist 
Sent: Wednesday, November 21, 2001 7:10 AM
Subject: Grain'-n-grazin'


OK, Betty, I'll probably get in trouble on this one, but here goes:
1] We feed grain because it is cheaper than forage.
2] Good grazing is very expensive in terms of management inputs.
3] Feeding perfectly good alfalfa to a bunch of blankety-blank sheep is a waste of resources.
                           [ack! ack! Off with 'is head!]
On the other hand:
4] There is little doubt in my mind that grazing good quality pasture is beneficial to the health of the animal.
5] Forage consumption and grazing in particular tends to increase the amount of omega-3 fatty acids, conjugated linoleaic[sp?] acid, and beta carotene in the fat deposits and milk fat of ruminants. This is a good thing.

Let's back up and punt. 
On adult sheep [and cows] on maintenance diets, almost all of the nutrients the animal eats winds up as ammonia and proprionic acid. The proprionic acid is absorbed directly through the rumen and used as an energy source, converted to glucose, glycogen etc. The ammonia grows bacteria that pass on to the other stomachs and are digested for protein. The creed in ruminant nutrition is to "feed the rumen[bacteria]." and let the rumen feed the sheep or the cow.

We feed the sheep X pounds of protein and Y pounds of energy [expressed as TDN or total digestible nutrients] each day, dependant on body weight, growth requirements, lactation requirements and so on. Feed consumption varies directly according to size, so a maintenance diet [dry cows and non-lactating ewes and guys watching football] need 11-12% crude protein and 62-66% TDN. High producing cows, ewes feeding twins, and fast growing young lambs need 16-18% protein and 74-76% TDN. This is equivalent to a person running a marathon...every day. 

The cheapest source of protein is soybean oil meal. The cheapest source of energy is corn. If top quality alfalfa hay is priced according to soybean meal and corn, the cost is twice its value as a feedstuff. Here in the South, alfalfa has significantly less energy value than it does in the North.

 For lactating ewes, alfalfa hay has to be supplemented with corn to provide adequate energy for a complete ration. Corn silage is high in energy value and needs to be supplemented with soybean or cottonseed meal to provide a complete ration.  Medium quality hay needs a grain ration that is some of each, generally 25% SOM and 75% corn [a 16% grain ration].

In maintenance diets, on the other hand, good alfalfa oversupplies protein and corn silage oversupplies energy. Neither is a "good" ration component for those that don't need it.

 When grazing, on the other hand, careful management is required to maintain the forage in a vegetative state to provide energy values of 66-70% TDN which will support lactation or active growth of lambs. Good flavor and tenderness of lamb has little to do with grain feeding and everything to do with sustaining fast, consistent growth rates. This probably applies to fleece growth as well. Worms and spells of poor nutrition lower quality. Grass that is grazed in a more mature state has drastically reduced energy and protein levels and is not likely to support growth without supplemental grain. As an alternative, we leave ewe lambs with their dams, where they can continue to nurse for several months. 

The idea of grazing pastures in rotation with horses is a good one. Grasses, sheep and internal parasites all evolved together into a 3 week or so cycle. This means that a 3 week rotational grazing plan places the sheep back into a pasture that is optimal for reinfestation with worms. Breaking this cycle with horses [which have different parasites] breaks this cycle. The same thing can be accomplished by harvesting hay from these paddocks in-between grazing cycles.

The key to recovering the increased costs that come from this higher management is niche marketing. 

Neal Grose

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